Default class members generated by C++

[BeautifulMind]

Hi,
As per the C++ standard, after the compilation of the following class
"Test" how many / which members would be generated by the compiler.
and actually I am also interested behind the logic doing so by C++ for
this empty class "Test" which is not even utilized in the program.

#include <iostream>
using namespace std;

class Test
{
};

void main()
{
}

Many Thanks

[Daniel T.]

Re: Default class members generated by C++

"BeautifulM ind" <msjammu@gmail. comwrote:

As per the C++ standard, after the compilation of the following class
"Test" how many / which members would be generated by the compiler.
and actually I am also interested behind the logic doing so by C++ for
this empty class "Test" which is not even utilized in the program.
>
#include <iostream>
using namespace std;
>
class Test
{
};
>
void main()
{
}
>
Many Thanks

I don't think any members are *required* to be generated. The "as if"
rule kicks in and since Test isn't used, the compiler need to nothing
with it.

[Neo]

Re: Default class members generated by C++



On Jan 29, 4:16 pm, "BeautifulM ind" <msja...@gmail. comwrote:

Hi,
As per the C++ standard, after the compilation of the following class
"Test" how many / which members would be generated by the compiler.
and actually I am also interested behind the logic doing so by C++ for
this empty class "Test" which is not even utilized in the program.
>
#include <iostream>
using namespace std;
>
class Test
{
>
};
>void main()
{
>
}Many Thanks

Hi,
For above mentioned code nothing will be generated as you have not
used Test class anywhere.
but if the code is

void main()
{
Test obj;
}

Only one bye of will be added as hidden data member. This is to
differentiate among the other instances of same class. default ctor/
dtor, copy ctor and assignment operator will not get generated coz
there is no any need.

Regards
Vikram S

[BeautifulMind]

Re: Default class members generated by C++

Hi thanks for the reply,

>For above mentioned code nothing will be generated as you have not
>used Test class anywhere.

class Test
{
};
void main()
{
}

So this means that given the above code, the compiler will remove the
Test class altogether from the object code (which it should I guess)
becuase it is not unilized anywhere?

Regards,
BeautifulMind

[Ian Collins]

Re: Default class members generated by C++

BeautifulMind wrote:

Hi thanks for the reply,
>
>

>>For above mentioned code nothing will be generated as you have not
>>used Test class anywhere.

>
>
class Test
{
};
void main()
{
}
>
So this means that given the above code, the compiler will remove the
Test class altogether from the object code (which it should I guess)
becuase it is not unilized anywhere?
>

unilized? Yes and no, the class is empty, so there isn't anything to
remove.

The compiler will get upset with you for writing "void main()".

--
Ian Collins.

[Daniel T.]

Re: Default class members generated by C++

"BeautifulM ind" <msjammu@gmail. comwrote:

Hi thanks for the reply,
>

For above mentioned code nothing will be generated as you have not
used Test class anywhere.

>
class Test
{
};
void main()
{
}
>
So this means that given the above code, the compiler will remove the
Test class altogether from the object code (which it should I guess)
becuase it is not unilized anywhere?

As an absolute? There is no telling. That's a quality of implementation
issue.

The compiler certainly _can_ remove the class, and I think it is safe to
say that, given the correct options, most _do_ remove the class, but
there is no guarantee that all compilers _will_ remove it.